The present invention relates to a package for synthetic bioabsorbable surgical articles and, more particularly, to such a package which is at least partially transparent for product visibility. More particularly, the invention relates to a package in which a first panel fabricated from a transparent, flexible polymeric laminate film possessing an inorganic moisture vapor transmission barrier layer is bonded along its edges to the edges of a second panel fabricated from a transparent, flexible polymeric film possessing an inorganic moisture vapor transmission barrier layer or from a moisture impermeable, opaque, flexible metal foil laminate to form a contents-enclosing pouch therebetween, the pouch containing a quantity of desiccant therein. This arrangement permits the contents of the package to be viewed without having to first open the package, an event which would only compromise the sterility of the contents.
The packaging of moisture-sensitive materials, devices, etc., in flexible packages manufactured in their entirety from metal foil laminate is universally practiced. Packages of this kind are widely used for the packaging of polymeric absorbable surgical clips and staples which are prone to degradation resulting from prolonged contact with moisture. Metal foil laminates have an immeasurably low water vapor transmission rate and provide a complete barrier to water vapor transmission which has heretofore been believed necessary for packaging polymeric absorbable products. Unfortunately, however, metal foil laminates are necessarily opaque and as a result, a package made from such laminates does not permit visual identification or inspection of its contents without being opened.
U.S. Pat. No. 3,256,981 describes a flexible package for sutures possessing a metal foil laminate as one of its sides and a transparent film of a polytrifluoroethylene film exhibiting a low water vapor transmission rate (Allied Chemical Company's Aclar.RTM. film) as the other. This package has not been accepted for the packaging of bioabsorbable surgical devices to protect such devices from moisture-induced degradation over extended periods. Indeed, prior to the present invention, it was generally accepted that foil laminate packaging was the only suitable packaging for synthetic absorbable articles and that moisture pervious packages such as described in U.S. Pat. No. 3,256,981 were incapable of adequately protecting such articles. The high cost of the polytrifluoroethylene film used in the construction of the package of U.S. Pat. No. 3,256,981 is believed to have been an additional factor further discouraging its use for the packaging of synthetic absorbable articles.
Transparent films useful for the construction of flexible packages possessing low water vapor transmission rates but avoiding the high cost of a polytrifluoroethylene film are known from, among others, U.S. Pat. Nos. 3,442,686, 4,528,244, 4,702,963 and 5,084,356.
U.S. Pat. No. 3,442,686 describes a transparent, flexible packaging film laminate consisting of a polymeric base sheet such as polyethylene terephthalate film having a heat-sealable top coating of a film-forming polymer such as polyethylene and an intermediate gas and liquid barrier layer of an inorganic material such as a silicon oxide.
The flexible packaging film of U.S. Pat. No. 4,528,234 includes a polymeric base film or sheet, a thin layer of at least one metal such as aluminum, tin, iron, zinc or magnesium formed on the base film or sheet by vacuum deposition or sputtering and a carboxyl group-containing polyolefin layer formed on the metal layer by lamination.
U.S. Pat. No. 4,702,963 describes a transparent, flexible packaging film possessing a thin layer of chromium formed on a polymeric film substrate layer and a thin layer of a glass material, e.g., a silicon oxide, formed on the chromium layer.
U.S. Pat. No. 5,085,356 discloses a transparent, flexible packaging film in which a glassy coating of silicon dioxide heavily doped with at least one of antimony, aluminum, chromium, cobalt, copper, indium, iron, lead, manganese, tin, titanium, tungsten, zinc or zirconium is applied to a polymeric film substrate.
A common strategy for dealing with moisture which may have penetrated a sealed package containing moisture sensitive goods is to insert a desiccant within the package. Known desiccant materials and desiccant units include molecular sieves such as zeolite Z-12 (U.S. Pat. No. 3,301,788), silica gel packaged between two sheets of nylon mesh bonded with a microporous polyurethane (U.S. Pat. No. 3,326,810) and a desiccant material such as alumina, bauxite, anhydrous calcium sulfate, water-absorbing clay, zeolite, or the like, optionally including a moisture sensitive color indicator such as cobalt chloride to indicate when the desiccant is "used up", in a binder of prepolymerized polyurethane resin (U.S. Pat. No. 4,036,360).